The idle system is designed to prepare a combustible mixture at a low engine speed. Correct idle setting will reduce the CO content in the exhaust gases and ensure the reliable operation of your engine.
Instructions
Step 1
Read how to adjust the engine idle speed using the example of domestic VAZ cars:
Warm up the engine to 70-80 degrees. To do this, you need to drive 5-7 km, because in idle mode, the oil will not be able to warm up enough.
Step 2
Find a low speed screw in the carburetor area, the so-called "quantity screw". Next to it there is a "quality screw", i.e. fuel regulating needle. These two screws are required for adjustment.
Step 3
Adjust the specified revolutions with the above-described "quantity screw" (for VAZ it is 859 rpm).
Step 4
Adjust the "quality screw" to achieve the maximum engine speed.
Step 5
When the maximum speed is reached, reduce it to the nominal with the “quantity screw”, and again increase it with the “quality screw” to the maximum.
Step 6
When reaching 840-850 rpm, set the "quality screw" to the position of the engine, bordering on stopping (the engine periodically shakes).
Step 7
Then unscrew the “quality screw” back 1/3 of a turn, i.e. get stable engine operation at the maximum lean fuel mixture.
Step 8
Check the operation of the system. At the optimum setting, the "quality screw" is unscrewed from the end position by 2, 0 - 2, 5 turns. The engine speed should drop when the "quality screw" is turned in any direction. The fuel jet of the system must be screwed in all the way, and the air jet must not be dirty.
Step 9
Adjust engine idle speed based on tachometer and gas analyzer readings. Correct adjustment will maintain an acceptable level of CO in the exhaust gases. Please note that on vehicles with a long service life, after adjusting the idle speed, sometimes there are problems when starting a cold engine. In such cases, the "quality screw" is slightly unscrewed back, but after that watch the CO level.
